442 PRACTICE OF PHYSIC. 



" We can say from a good deal of experience, that opiates 

 have been very generally useful in the cure of this disease. 

 M.M. 



SECT. II. OF THE SPASMODIC AFFECTIONS OF 

 THE VITAL FUNCTIONS. 



CHAP. IV.* OF THE PALPITATION OF THE 

 HEART. 



MCCCLV. The motion thus named is a contraction or sys- 

 tole of the heart, that is performed with more rapidity, and 

 generally also with more force than usual ; and when at the 

 same time the heart strikes with more than usual violence against 

 the inside of the ribs, producing often a considerable sound. 



MCCCLVI. This motion or palpitation is occasioned by a 

 great variety of causes, which have been recited with great pains 

 by Mr. Senac, and others ; whom, however, I cannot follow in 

 all the particulars with sufficient discernment, and therefore 

 shall here only attempt to refer all the several cases of this dis- 

 ease to a few general heads. 



MCCCLVII. The first is of those arising from the applica- 

 tion of the usual stimulus to the heart's contraction ; that is, 

 the influx of the venous blood into its cavities, being made with 

 more velocity, and therefore, in the same time, in greater quan- 

 tity than usual. It seems to be in this manner that violent ex- 

 ercise occasions palpitation. 



MCCCLVIII. A second head of the cases of palpitation, is 

 of those arising from any resistance given to the free and entire 

 evacuation of the ventricles of the heart. Thus, a ligature 

 made upon the aorta, occasions palpitations of the most violent 

 kind. Similar resistances, either in the aorta or pulmonary ar- 

 tery, may be readily imagined; and such have been often found 

 in the dead bodies of persons, who, during life, had been much 

 affected with palpitations. 



To this head are to be referred all those cases of palpitation 



* Though I have thought it proper to divide this book into sections, I think it necessary, 

 for the convenience of references, to number the chapters from the beginning. 



